Honing mandrel



April15,1947.' AHALSTY 2,419,136

HONING MANDREL Filed April 25, 1945 HVVENTUR. ffl/ber! H453/ PatentedApr. 15, 1947 UNITED STATES PATENT OFFICE HONING MANDR'EL Albert F.Hasty, Detroit, Mich.

Application April 25, 1945, Serial No. A590,139

Claims. 1

This invention relates to honing devices and it has to do particularlywith va mandrel construction for Vholding abrasive elements or stonesfor the honing of the interior surfaces of previously formed holes orapertures.

It is the aim of the invention to provide an improved mandrel structurefor adjustably holding the stones so that they can be adjusted to thedesired diameter. The term stone is employed in 'a broad sense coveringan abrasive element.

One object of the invention is to provide an improved construction wherethe stones are held and maintained in position on the mandrel. To thisend the arrangement and construction is such that the forces, incidentto the honing operation, do not tend to lift the stones from theirseats. To the contrary, the applied forces tend to seat the stones inposition. A further object is to provide a mandrel-type hone structurewhich will minimize the tendency to bell the ends of an aperture. Insome structures heretofore employed the honing surface of the stonesvaried in area as the stones tapered from one end to the other.` Withthis construction one end of an aperture would be subjected to moreabrasive action than the other resultingy in a helling or enlarging ofthat end of the aperture. In laccordance with the present invention thehoning surface is oi substantially equal area from one end of the honeto the other so that the abrading action is uniform throughout the axialextent of a hole thus minimizing or eliminating the belling action.

Further objects include the provision of a inea-ns for holding thestones on the mandrel but providing for easy and quick adjustment andfor ease or facility in removing and replacing the stones. These andother objects will be better appreciated as the following detaileddescription is considered.

The drawings illustrate a structure for carrying out the invention. Inthese drawings:

Fig. 1 Vis a view partly in cross section illustrating a honing mandrelconstructed in accordance with the invention and showing the stones inposition thereon.

Fig, r2 is a perspective View of a stone on its vseat or holder.

Fig. 3 is a sectional view taken substantially .line 3-3 of Fig. lshowing some of the holding structure.

Fig. 4 is a sectional view taken substantially on line lf- 2lillustrating the stones in seated position.

Fig. 5 is a view taken on line 5-'5 of Fig. l

showing the structure near the end of the stones.

Fig. 6 is an enlarged sectional view taken substantially on line yli-tof Fig. l showing some of the end structure or mandrel.

Fig. '7 is a detailed view looking in the direction of the line 'l-l ofFig. 1.

A suitable chuck of a machine Aor rotary driving element is illustratedat l and associated with the machine is an axially adjustable element 2.This element is capable of manual adjustment axially and it has aconnection with the bar of the mandrel yas will later appear.

As will be noted by reference to Fig. 2, an abra-ding element or stoneis illustrated at 3. A suitable holder `therefor is yprovided and thismay be fashioned from sheet metal. The holder has a bottom plate i (Fig.4). The kstone isy provided with an arcuate 'abrading surface 5 with twoopposite straight faces l rand 'i and a bottom surface or face 8 whichseats upon the plate 4. The stone is held to the plate by a suitableadhesive so that the stone is securely held in position. One edge oftheholder is fashioned into the form of a flange l2, the height of whichvaries for reasons which will presently appear and at the end the metalis fashioned to provide a key I3. Secured as by means of Welding or thelike to the underside of the plate s is a holding rod or wire ll!- witha turned up end I5.

The vbar oi the mandrel is generally illustrated at it. This bar isprovided with oppositely disposed longitudinally extending slots Il andI8' lfor the reception of the holding rods I4. In the forward portion ofthe bar the same is provided with milled or otherwise oppositely formedrecesses for receiving the stones and their holders. This will beapparent by reference to Figs. 4 and 5. The bottoms of the oppositerecesses are vdefined by an integral center piece or web 2B while thesides of the recesses are formed by the remaining vstock of the bar asillustrated at 2l and 22 for one recess, and 23 and 24 for theoppositerecess. The center piece 29 is of tapering form, the same beingrelatively thin near the end of the bar as shown in Fig. 5 randgradually uickening in cross section to about the location :c where thesurfaces may merge with the peripheral surface of the forward portion ofthe bar.

The holding plates 4 rest upon this center piece as indicated in Figs. 4and 5 while the holding rods or wires I4 lie in the slots I l and I'8.Obviously two opposed stones and holders are applied as illustrated. Atthe forward end of the bar the same is provided with key ways orgrooves, one for each key i3. These keyways are f -drel bar.

',other. place one or more stones the cap 40 is given a illustrated atand 26 (Fig. 6). Since the recess formation gradually diminishes indepth from the free end of the bar toward its base end, the flanges I2are likewise of tapering width.

It will be apparent from the description thus far that the stones withtheir holders may be disposed upon the bar, the same being located inthe recesses with the holding plates resting upon the bottom of therecesses. One side of each stone lies against one side of its recess asat 2l and 24 while the flange I2 is embraced by the opposite recess wallas at 22 and 23. The keys I3 are positioned in the grooves 25 and 26,this being accomplished by relative axial movement. It will also beappreciated that relative axial movement between the bar and the stoneholders will serve to radially adjust or expand the stones relative toeach other.

The opposite end of the mandrel structure embodies a driving sleevearranged to be gripped by the 'chuck I. This sleeve has a bushing 3| atone end and a collar or bushing 32 at its opposite end, the mandrel barbeing received therein. The bushing 3l is slidable in the sleeve 30 butis rotatably held with the sleeve as by means of a screw 33 positionedin a slot 34. The end of the bar is connected to the adjusting element 2as by means of an interconnecting bayonet-type connection 35. Themandrel bar is connected in driving relationship with the bushing 3| asby means of a key or drive pin 36. Thus, rotation of the sleeve 36causes rotation of the bushing and the mandrel bar.

There is a cap 40 positioned over the opposite end of the sleeve 30 andit has an apertured bottom 4I through which the mandrel bar extends.This cap has oppositely disposed slots 42 (Fig. 3) for the ends l5 ofthe holding bars I4. A screw 45 passes through the sleeve 30 and isthreaded into the bushing 32, this screw serving to thus connect thesleeve and bushing 32. This screw extends through an inclined slot 46 inthe cap 4U. The end of the sleeve 30, which lies within the cap, isprovided with opposite notches 50 which receive the holding bar ends I5.

Assuming that the assembly is in its completed form as shown in Fig. 1,rotation of the chuck causes rotation of the bar and, therefore,rotation of the stones. As is well known to those versed in the art, thework piece, with its aperture, is to be passed over the rotating stonesby relative movement between the work piece and the mandrel which can beaccomplished by axial movement of the work piece or by movement of themandrel. The stones, through their holders, vare held in a fixed axialposition on the mandrel by the holding bars I4 and their ends I5 whichare lockedin their grooves 50 by the cap 40. If it is desirable toexpand the stones and thus increase the effective honed diameter theadjusting piece 2 is manipulated to advance the man- By advance is meantthat the bar is shifted to the right as Fig. 1 is viewed. Thus, thecenter web 26 provides a wedging action as it shifts or advancesrelative to the stones and the stones are relatively. expanded. The keysI3 slide in their` ways 25 and 26 and thus retain their stone holders inposition. If the mandrel is retracted the stones are retracted towardeach If and when it becomes necessary to repartial turn and the camaction of the slot 46 on the screw 45 backs the cap away from the endportions I5. The stones and their holders may now be removed by shiftingthe same axially relative to the mandrel bar. New stones and holders maybe assembled by the reverse operation until the bar ends I5 are seatedin their recesses 56 and the keys I3 positioned in their Ways 25 and 26.The cap is now given partial rotation to position the same substantiallyas illustrated in Fig. 3, and the new set of stones are assembled.

It will be observed that the angular extent of the exposed honingsurface 5 of the stones is substantially uniform from one end to theother. As a result there is a substantial equal honing action over theentire internal surface of a work piece aperture. Accordingly, anytendency to bell the entrance of an aperture is minimized. It will alsobe noted that the cross section of the stones is such that they areprovided with a wide supporting base, the transverse dimension of whichsubstantially equals a chord of the arcuate honing surface. Thispromotes stability in the stone mounting as there is no tendency to liftthe stones from their seats during the hon. ing operation. This is'diagrammatically illus. trated in Fig. 5. If the rotation iscounter-clockwise, the forces on the stone are resolved into a componentsubstantially in the direction as indicated by the arrow 55. This tendsto seat the stone and is contrary to forces at the leading edge of thestone which may tend to lift or un. seat it.

I claim:

1. A honing mandrel comprising, a mandrel bar having one end adapted tobe engaged and rotated, said bar having oppositely disposed U- shapedchannels extending lengthwise from a mid-portion thereof to the free endthereof, the sides of the channels being substantially straight andparallel to each other, the bottoms of the channels being defined by anintervening web and said bottoms being substantially flat and at rightangles to the sides, said web being of gradually thickening and taperingwedge-like form with its thinnest portion at the free end of the bar, astone holder comprising a holding plate, a stone seated upon and securedto the plate, there being a stone holder and stone positioned in eachchannel with the plates resting upon the web, a lati erally projectingkey on each plate, a lateral groove in each channel adjacent the freeend of the mandrel bar and having a longitudinal extent greater thanthat of the key, each key being disposed in one of the grooves, saidstone holders with their stones and the mandrel bar adapted to berelatively adjusted longtiudinally whereby the stones are radiallyadjusted.

2. A honing mandrel comprising, a mandrel bar having one end adapted tobe engaged and rotated, said bar having oppositely disposed U- shapedchannels extending lengthwise from a mid-portion thereof to the free endthereof, the sides of the channels being substantially straight andparallel to each other, the bottoms 0f the channels being defined by anintervening web and said bottoms being substantially fiat and at rightangles to the sides, said web being of gradually thickening and taperingWedge-like form with its thinnest `portion at the free end of the bar, astone holder comprising a holding plate, a square-sided flat-bottomedstone seated upon and secured to the plate, said stone having an arcuatesurface opposite its flat bottom and said stone tapering in thicknessfrom end to end corresponding to the wedge-like form of the web, therebeing a stone holderl and stone positioned in each channel, an axiallyextending groove in Y each channel near the free end of the bar, a keyon each holder for disposition in each groove and means for securing theholders against axial movement on the mandrel bar and for relativelengthwise adjustment of the mandrel bar relative to the holders.

3. A honing mandrel comprising, a mandrel bar having one end adapted tobe engaged and rotated, said bar having oppositely disposed U shapedchannels extending lengthwise from a mid-portion thereof to the free endthereof, the sides of the channels being substantially straight andparallel to each other, the bottoms of the channels being defined by anintervening web and said bottoms being substantially flat and at rightangles to the sides, said web being of gradually thickening and taperingwedge-like form with its thinnest portion at the free end of the bar, astone holder comprising alholding plate, a square-sided flat-bottomedstone seated upon and secured to the plate, the stone having an arcuateabrading surface opposite its ilat bottom, the angular extent of thearcuate abrading surface being substantially uniform from one end of thestone to the other end, the stone being of tapering thicknesscorresponding to the wedgelike form of the web, there being a stoneholder and stone positioned in each channel with the plates resting uponthe web, a laterally extending groove in each channel located near thefree end of the mandrel bar, a key on each holder for disposition in thegrooves, means for securing the holders in a xed axial position andmeans for axially adjusting the mandrel bar relative tothe holders.

4. A honing mandrel comprising, a mandrel bar having one end adapted tobe engaged and rotated, said bar having oppositely disposed U- shapedchannels extending from a mid-portion thereof to the free end of thebar, the sides of the channels being substantially straight and parallelto each other and the bottoms of the channels being deiined by anintervening web, said bottoms being substantially at and disposed atright angles to the sides, said web being of gradually thickening andtapering wedge-like form with its thinnest portion at its free end ofthe mandrel, each channel having a laterally extending groove adjacentthe free end of the bar,

a stone holder comprising a plate, said plate having a flange extendingalong one edge and having a laterally projecting key at one end, asquare-sided flat-'bottomed stone secured on the plate with one sidethereof abutting the flange, there being a stone holder and stonepositioned in each channel with the plates resting upon the web and withthe key of each holder being disposed in a laterally extending groove,and means for relatively adjusting the mandrel bar and the stone holderswhereby the wedge-like web serves to radially adjust the stone holders.

5. In a honing mandrel, a mandrel bar, a sleeve adapted to be grippedand rotated by a turning instrumentality, means slidably keying themandrel bar to the sleeve, means for adjusting the mandrel bar axiallyrelative to the sleeve, said mandrel bar projecting from the sleeve, apair of stone holders mounted on the projecting portion of the mandrel,said mandrel having longitudinally extending grooves therein, rod-likeVmembers extending from the stone holders and having outwardly turnedends, said rod-like members lying in the longitudinally extendinggrooves, the sleeve having notches at one end for receiving theoutwardly turned ends of the rod-like members, a cap positioned over theend of the sleeve and having an aperture through which the mandrelbarextends, the outwardly turned portions of the rod-like members beingdisposed beneath the cap and held in the notches thereby, cam actingmeans for securing the cap to the sleeve whereby upon turning the capits bottom is backed aWay from the end of the sleeve, the bottom of thecap havin-g slots therein for alignment with the said ends of therod-like members for the passage of the said ends thereof through theslots in assembling and disassembling the stone holders from the mandrelbar.

' ALBERT F. HASTY.

file of this patent:

UNITED STATES PATENTS Name Date Staples Aug. 1, 1944 Number

